1. Field of the Invention
The present invention relates to wireless communications and, more particularly, to wireless communication of packet-based real-time media.
2. Description of Related Art
As a general matter, it is known for a wireless device to engage in packet-based real-time media communication with one or more other entities. In particular, such a device could be equipped to engage in packet-data communications via a radio access network, and to send and receive media in real-time as packet data.
An example of such a device is a cellular mobile station of the type that might communicate over an air interface with a base station and in turn with a gateway that provides connectivity with a packet-switched network. Such a mobile station can be equipped with hardware and program logic to be able to digitize, encode and packetize real-time media and transmit resulting media packets via the packet-switched network. Further, the mobile station can be similarly equipped to receive and de-packetize incoming media packets from the network and to decode and play out the underlying media to a user.
In this manner, the wireless device can allow a user to engage in real-time communication with one or more other users, each of whom operates another device that also has access to the packet-switched network. Such communication could be peer-to-peer, in that the devices exchange media packets with each other. Alternatively, the communication could be bridged through a central conference server of some sort, in which case each device would engage in packet-based media communication with the server and the server would bridge the communications together to allow the users to communicate with each other.
Wireless connectivity, however, presents a challenge for this sort of real-time communication. The difficulty stems from the fact that, in many wireless communication systems, the wireless connection through which packet-data passes between a wireless device and a radio access network will time out after a certain period of inactivity (i.e., absence of packet-data flow). Thereafter, in order for the device to send or receive further packet-data, the device must re-acquire a radio link. But the process of acquiring a radio link can sometimes take on the order of 6-10 seconds.
During a packet-based real-time media session, if a long pause in communication occurs such that none of the participating devices are sending or receiving media packets for longer than the radio link time-out period, a participating wireless device may lose its radio link. In turn, if that device seeks to send or receive further media packets, significant delay could occur as the device works to re-acquire a radio link. This delay can be disruptive and therefore undesirable.